1. Field of the Invention
The present invention relates generally to a micro-electro-mechanical system (hereinafter referred to as “MEMS”) sensor having a moveable sensing element and more particularly, to a multifunctional MEMS sensor capable of sensing acceleration and pressure simultaneously.
2. Description of the Related Art
MEMS sensors, including but not limited to inertia sensors, such as accelerometers and gyroscopes, pressure sensors and gas sensors, are intensively used in many fields, such as cars, computers, consumer electronic devices, communication devices and etc. Many MEMS sensors include one or more moveable sensing elements, which are so-called “proof masses.” For example, U.S. Pat. No. 4,905,523 disclosed a force detector and a moment detector. By means of detecting the value changes of the resistances representing the stress-strain variation caused by movement of the proof mass, the change of the external force can be indirectly detected.
In some electronic products, two or more sensors may be used. For example, a pressure sensor and an accelerometer may be equipped inside a laptop for sensing the ambient pressure and the posture of the laptop simultaneously. However, a certain space will be occupied for the installation of the two individual sensors in an electronic product. In other words, the aforesaid nowadays design can not fulfill the market demand for small, thin and light electronic product. In addition, using two individual sensors also increases the costs of the electronic product.